Electric hammer



Dec. 9, 1924,

L. PAULERO ELECTRI O HAMMER Filed March 50, 1920 4 Sheets-Sheet 1 Inventor Louzs Paula/ By orrzey Dec. 9, 1924- L. PAULERO ELECTRIC HAMMER Filed March 50, 1920 4 Sheets-Sheet 2 hive r Lauw aulero,

rrzqy Dec 9, 1 4. 1,518,273

| PAULERO ELECTRIC HAMMER Filed March 50, 1920 4 Sheets-Sheet 5 Inventor L 0 u is Paula/"0,

g www Dec. 9, 1924- 1,518,273

L. PAULERO ELECTRIC HAMMER Filed Marph 30, 1920 4 Sheets-Sheet 4 i MA Z: Q 10 {I 43 'IIIIIIIllI/II.

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UNITED STATES 1,518,273 PATENT OFFICE.

LOUIS PAW, OF PETEBSBUBG, VIRGINIA.

ELECTRIC BARKER.

annals fled ma :0, man. Serial in. 370,030.

To all whom it may concern:

Be it known that I, LOUIS Pammno, a citizen of the United States, residing at Petersbur in the county of Dinwiddie and State of i ir inia, have invented certain new and useful provements in Electric Hammers, of which the following is a specification.

This invention relates to improvements in electric hammers wherein are employed a tool actuatin anvil, a reciprocatable lunger for striking the anvil, solenoid coils or actuating the plunger, contact making and breaking devices for supplying electric current to the coils, means whereby the pres sure of the tool against the work causes the closing of the contact devices for the actuation of the plunger, and adjustable means for varying the length of the stroke of the plunger to regulate the force of the blows struc thereby.

An object of the present invention is to improve the contact making and breaking devices, whereby the parts thereof may be easily assembled and disassembled and inserted into or removed from the hammer for the repairing or renewal of parts and for other pur ses.

Another ob ect of the invention is to improve-the construction and arrangement of the plunger and striking anvil, and to provide a novel, simple and eflicient means for regulating the length of the stroke of the plunger.

A further object is to improve the solenoid spools and the means for holding them in place and to provide novel means for permitting the electrical connections thereto and to the contact making and breaking devices to be easily made.

Also, the invention aims to provide a novel hammer the parts of which are constructed and o anized so as to render the hammer adapta le for under water work and especially useful to deep sea divers.

\Vith the above and related objects in view, the invention consists in the novel construction and combination and arrangement of parts hereinafter described and claimed.

In the accompanying drawings, illustrating the invention, 1

igure 1 is a side view of an electric hammer embodying my invention.

Figure 2 is a longitudinal section thereof.

Figure 3 is a detail of the tool receiving end of the hammer as seen from the top of Fig. 1, showing the lockin device for the ad ustable head for regulating the stroke of the plunger.

Figure 4 is an enlarged longitudinal Section through the tool receiving end portion of the hammer.

Figure 5 is a diagrammatical view showing the electrical connections.

Figures 6, 7, 8 and 9 are transverse sections through the hammer, on lines 6-6, 7-7, 88 and 99, respectively, of Fig. 2.

Figure ,10 is a face view of one of the discs of insulatin material. carrying parts of the contact ma ing and breakm device.

Figure 11 is a side view of t e parts shown in Fig. and adjuncts.

Figure 12 is a face view of the other disc of insulating material carrying parts of the contact making and breaking device;

Figure 13 IS a side view ofthe parts shown in Fig. 12 and adjuncts.

Figure 14 is a sectional detail showing one of the spring pressed contact pins and parts co-operating therewith for making and breaking electrical contact.

The frame structure of the hammer comprises a cylindrical casing member 10, an extension casing member 11 and a handle member 12. The member 11 is screwed on to one end of the member 10 and forms an extension thereof, being reduced in diameter The handle member-12 comprises a hollow head or cap 13, which is screwed on to the other end of the member 10, and a hollow handle grip14 cast integral with the head 13 and extendin therefrom, as illustrated. One side of the ead 13 is split, at 15, and provided with projecting lugs 16 throu h which a clampin bolt 17 extends for t e purpose of drawing the sides of the head 13 together and thereby firmly clampin it in place upon the member 10, after it i118 been screwed thereon. The members 10, 11 and 12 when assembled are, in effect, a single element and they are made separate only to permit the introduction thereto of the parts which they contain and for convenience of assembling.

Within the casing member 10 is a solenoid spool 18 upon which are wound two solenoid coils 20 and 21, respectively. The spool 18 is formed of suitable non-magnetic material, preferably brass, and it comprises alined, gylindrical cores 22 and 23, and projecting anges 24 and 25 between which the coils 20 and 21 are wound upon the cores 22 and 23, respectively. The inner or adjacent spool flanges 24 and 25 are slightly spaced from each other and are connected by an ins 001 18 an terposed rin .28 which forms part of the which is larger in diameter an the cores 22 and 23. The spool 18 is held in place against longitudinal displacement within the casing member 10 by being clamped by and between shoulders 29 and 30 formed in the head 13 and member 10 and engaging the adjacent spool flanges 24 and 25, respectively. The spool flanges 24 and 25 are fitted to the inner wall of the casing member 10 to hold them centrally therein; and they are prevented from turning within the casing member 10 by a key 26 carried by the member 10 and extendin into slots or grooves in the adjacent spoo flanges 24 and 25. The key engages the inner wall of the casing member 10 and the central portion of the key extends outwardly through and beyond a slot in the member 10 and is riveted against a plate 27 which is fitted against the'outer face of the member 10 and surrounds the outwardly projecting. part of the key 26.

Slidably fitted within the cores 22 and 23 of the solenoid spool 18 is a cylindrical steel plun er 31 which is adapted to be reciprocate by the solenoids 20 and21. The plunger 31 is arranged between and i adapted to strike against a cushion spring 32, at one end of its stroke, and a cylindrical anvil 33, at the other end of its stroke. The spring 32 and anvil 33 extend into the cores of the solenoid spool 18, and the spring 32 is held in place by having its outer end expanded between the outer end of the spool core 22 and a ring 34 which is screwed into a cylindrical extension 35 on the outer spool flange 24. The rin 34 has a transverse slot 36' therein for t e reception of a suitable tool to turn the ring 34 when it is screwed into or out of the extension 35.

The insulated wires 36, 37 and 38 for supplying electric current to the solenoids 22 and 23 extend through the head 13 and the hollow handle grip 14 and through a suitable cable 39 leading from a source of current to the hammer. The cable 39 extends through and is held within a cap screw 40 which is screwed'into the free end of the handle ip 14, and the end of the cable 39 within t e handle grip- 14 is embedded in a suitable cement compound therein to form a tight joint.

"The head 13 is provided with an opening 41 near-its junction with the handle grip 14' through which access may be had to the wires 36, 37 and 38 for the purpose of splicing them to other wires leading to the solenolds 20 and 21 and to contact making and uca-n breaking devices hereinafter described. The opening 41 is normally closed by a plug 42 which 1s screwed into the head 13 and provided with a slot to receive a. tool for turning it, and which may be removed and replaced when desired.

I shall now describe the contact making and breaking device for starting and stopping the actuation of the hammer by starting and stopping the supply of electric current to the solenoids 20 and 21.

Secured to the spool flange 25 farthest from the handle member 12 by means of screws 43 is a disc 44 of insulating material; and spaced from the disc 44 is another disc 45 of insulating material. The disc 45 is secured by .means of screws 46 to a metal disc 47 which is slidable within the casing member 10 toward and from the disc 44, the metal disc 47 being guided by the casing member 10 and by a sleeve 48 formed on the disc 47 and slidably fitted to the cylindrical anvil 33. The discs 45 and 47 are prevented from turning within the casing member 10 by projections 49 formed thereon which slide within a longitudinal groove 50 formed in the casing member 10. The disc 44 is prevented from turning relatively to the disc 45 not only by the spool 19 but also by a projection 51 on the disc 44 which enters the groove 50.

The insulating discs 44 and 45 are maintained normally spaced from each other, as shown in Fig. 2, by the interposition of coiled springs 52, 53 and 54. 'Theends of these springs adjacent to the disc 45 are attached thereto by being soldered or otherwise suitably secured to separate plates, 55, 56 and 57, respectively, which are riveted to the disc 45. The ends of these springs adjacent to the disc 44 surround studs 58, 59 and 60 projecting from separate plates 61, 62 and 63 which are riveted to the disc 44. This construction causes the disc 45 to hold the springs 52, 53 and 54 in place at all times for proper registry with the studs 58, 59 and 60, and permits the springs to be separated from the disc 44 when the parts of the device are disassembled. The springs 52 and 53 perform the additional function of electrically connecting the plates 55 and 61 and the plates 56 and 62, respectively, to form parts of electric circuits hereinafter explained.

The plates 55 and 56 are provided with guiding sleeves 64 and 65 which project toward the disc 44. Slidable within the sleeves 64 and 65 are contact making and breaking pins 66 and 67 having end portions which project beyond the-free ends of the sleeves. The pins 66 and 67 are retained within the sleeves 64 and 65 by the free ends of spring arms 68 and 69 which extend through slots in the sleeves 64 and 65 and enter holes in the pins 66 and 67. The spring arms 68 and 69 are riveted or otherwise suitably secured to flanges pro'ecting from the plates 55 and 56, respectively.

The contact pins 66 and 67 are arranged in alinement with and normally s aced from contact heads 70 and 71 carried y separate plates 72 and 73 which are secured to the disc 44 by screws 74 and 75 and rivets under the heads 70 and 71. When the discs 45 and 47 are moved toward the disc 44 against the action of the springs 52, 53 and 54, the pins 66 and 67 are moved into electrical contact with the heads 70 and 71; and during this operation, the spring arms 68 and 69 yield within the slots in the sleeves 64 and 65 and permit the pins 66 and 67 to be pressed back y their engagement with the heads 70 and 71, thereby ensurin good contacts at both points. After the pins 66 and 67 have made contact with the contact heads 70 and 71, and the pressure against the discs 44 and 45 has been removed, the springs 52, 53 and 54 will return the parts to normal position to thereby break the contact between the pins 66 and 67' and heads 70 and 71.

The parts .of the contact making and breaking device just described are connected by wires, as shown diagrammatically in Fig. 5, to the three wires 36, 37 and 38, leading into the handle member 12 as follows:

The wires 36 and 37 are continued to the plates 72 and 73 by wires 76 and 77 which are secured thereto b 74 and 75, respective y; and the wire 38 is L continued to the adjacent or inner ends of the solenoid coils 20 and 21 by a wire 82 which is electrically connected thereto in any suitable manner. The other or outer ends of the coils 20 and 21 are connected by wires 78 and 79 to the plates .61 and 62, respectively, the wires 78 and 79 being attached to the plates by means of screws 80 and 81, as shown.

It will be observed that normally, or when the pins 66 and 67 are out of-contact with the heads 70 and 71, there is no electrical connection between the plates 61 and 74 or between the plates 62 and 73; and it will be observed also that when the pins 66 and 67 are moved into contact with the heads 70 and 71, electrical connection is established between the plates 61 and 72 and between the plates 62 and 73 through the heads 70 and 71, pins 66 and 67, sleeves 64 and 65, plates 55 and 56, and springs 52 and 53, respectively.

\Vhen the engagement of the pins 66 and 67 with the heads 70 and 71 electrically connects the plates 61 and 72, and the plates 62 and 73, current may be supplied to the coils 20 and 21 in rapid alternate succession. Taking the coil 20 as the first to be energized, the current will come into the hammer through the wire 36, wire 76, plates 61 end 72, and the contact making and breakmeans of the screws 7 ing device connecting them, and wire 78 to and through the coil 20 and will pass out from the coil 20 through the wires 82 and 38 which are common to both coils 20 and 21. The urrent in the next course thereof will come into the hammer through the wire 38. wire 82 to and through the coil 21 and will pass out through wire 79, plates 62 and 73, and the contact making and breaking device connecting them, and wires 77 and 37.

The means for causing electric current to take the two courses just described in rapid succession forms no part of my present in vention. The means which I prefer to use for this purpose, however, is disclosed and claimed in my Patent No. 1,362,349, dated December 14, 1920.

When the two solenoid coils 20 and 21 are energized in rapid succession, as above described, they cause the rapid reciprocation of the plunger 31 causing it to strike blows against the anvil 33 in rapid succession.

I shall now describe the means for closing the normally open contact making and breaking device for supplying the current to the coils 20 and 21 for the actuation of the plunger 31.

Within the extension member 11 of the casing is a cylindrical part 91 having an en- 'larged inner end portion 84 and a reduced outer end portion 85. This part 91 is held in place between a shoulder 86 formed in the member 11 and a fixed annular plate 87 which is screwed into the extension member 11 in advance of the casing member 10 and clamped between the adjacent end of the member 10 and a shoulder 88 formed in the member 11. The plate 87, after being screwed into place, is locked against accidental turning by a spring arm 93 carried thereby and having a projection 94 which enters a hole 95 in the member 11. The part 91 has a lar e axial bore 89 in the inner portion thereo and a smaller axial bore 90 in the outer portion thereof, and the anvil 33 penetrates the large bore 89 in spaced relation to the wall thereof and enters the small bore 90 and is slidably fitted thereto, as shown. The small bore 90, between the outer end of the part 91 and the end of the anvil 33 therein, is adapted to receive the shank 96 of a suitable tool 97. The anvil 33 and shank 96 are slidably fitted within the part, 91; and, when the outer end of the tool 97 is pressed against the work it is to act upon, the end of its shank 96 will engage the end of the anvil 33 and force it inwardly and thereby close the electrical contact device, as will resently appear. Fitted to slide longitudinal y within the large bore 89 of the part 91 is a sleeve 92 which surrounds the anvil 33 and which is carried thereby by being screwed on to a threaded enlargement 193 thereof. Between the disc 47 of the contact making and breaking device and the inner end of the sleeve 92 is rotatably fitted thereto. I which is screwed into the head 101 and are reciprocable pins 99 which penetrate the interposed plate 87 and. are slidably fitted to openings therein. By the aid of the sleeve 9.2 and pins 99, the electrical contact device will be closed when the pressure of the tool 97 against the work moves the anvil 33 toward the plunger 31 because when the anvil is thus movedit carries with it the sleeve 92 which moves the pins 99 and thereby moves the discs 47 and 45 toward the disc 44 against the action of the springs 52, 53 and 54. and moves the contact pins 66 and 67 into engagement with the contact heads 70 and. 71. The springs 52, 53 and 54 in holding the contact device open.'also hold the pins 99, sleeve 92 and anvil 33 normally in the position shown in the drawings, and return them to that position after they have been moved inwardly and released. The pins 99 are provided with heads 100 which prevent them from falling out accidentally when the extension member 11 is removed from the easmg member 10 and the discs 45 and 47 are removed from within the member 11.

The length of the stroke of the plunger 31 is varied to regulate the force of the blows struck thereby against the anvil 33, by varying the normal position of the anvil 33 relatively to the plunger 31. so that when the anvil 33 is moved inwardly by the tool 97 to close the contact device for the aetuation of the plunger, the distance between the cushion spring 32 and the anvil 33 will be varied, thereby varying the length of travel of the plunger 31 and consequently varying the force of the blows struck thereby; and I shall now describe the means for adjusting or varying the normal position of the anvil 33.

Screwed on to the outer end of the part 91 is a head 101 provided with a flange or collar 102 which extends back and around the extension member 11 of the casing and A screw 103 which enters the part 91 is provided to lock the head 101 and part 91 together and cause the part 91 to turn with the head 101 when the head 101 is turned by hand. Slidable longitudinally in an opening 104 in the member 11 is a block 105 which is pressed yieldingly toward the head 101 by a spring 106 within the opening 104 between the end wall thereof and the block 105. The block 105 is provided with an outwardly projecting arm 107 Which is adapted to enter any one of a number of'spaced notches 108 in the flange 102 of the head 101 to lock the head in different positions of adjustment. The block 105 may be moved back against the action of the spring 106 to release the head 101 by the thumb or finger of the workman using the hammer.

To cause the sleeve 92 to be turned with the part 91 when the head 101 is turned, I

provide the part 91 with a pin 109 which enters a longitudinal slot 110 in the sleeve 92 and permits the sleeve 92 to move longitudinally within the part 91 when the anvil 33 is moved. longitudinally therein; and to prevent the anvil 33 from turning when the sleeve 92 is turned, I provide the plate 87 with a collar 111 which projects into the part 91 and into the sleeve 92 therein, and which has a projection 112 extending into a longitudinal slot 113 in the anvil 33.

\Vhen the head 101, part 91 and therewith the sleeve 92 are turned,'for adjusting purposes, longitudinal movement of the sleeve 92 is prevented by the end wall of the large bore 89 in the part 91 and by the adjacent end of the pins 99, so that when the sleeve 92 is thus turned, the threads therein, acting upon the threads of the enlargement 193 on the anvil 33. will move or adjust the anvil longitudinally with respect to the means which causes its inward movement to close the electric contact device. Thus the anvil 33 may be set nearer or farther from the cushion spring 32 to vary the length of the stroke of the plunger 31, as desired, the direction of movement of the anvil 33 during the adjustment thereof being governed by the direction in which the head 101 is turned. After the anvil 33 has been adjusted, the parts associated therewith are held in the adjusted position by the engagement of the arm 107 with one of the notches 108, as the workman permits the spring 106 to return the block 105 to normal position.

The plunger 31 and the anvil 33 are each provided with a circular series of longitudinally extending grooves 114 and 115, respectively, as illustrated. These grooves 114 and 115 serve the double purpose of cutting up eddy currents and permitting the free passage of air within the solenoid chamber.

Surrounding the anvil 33 and seated within a groove in the part 91 is a packing ring 116, surrounding the part 91 and seated in a groove in the casing member 11 is a packing ring 117. and surrounding the member 11 and seated in a groove therein between it and the flange 102 of the head 101 is a packing ring 118. The purpose of the packing ring 116 is to prevent water from entering the tool between the anvil 33 and the part 91, and the purpose of the packing rings ,117 and 1.18 is to prevent water from entering the tool between the and the part 91 therein.

The outer end of the opening 95 is normally closed water tight by a removable screw plug which may be removed to permit the insertion of a suitable tool to disengage the projection 94 from the wall of the opening 95 when it is desired to unscrew the plate 87 from within the member 11.

The construction hereinbefore described casing member 11 down to proper provides a water tight casing which encloses the hammer mechanism and its electromagnetic actuating means so that the entire device may be submerged in water without danger of the water reaching the partswithin the casing, and so that when the hammer is thus submerged the water surrounding the same and in contact therewith will carry oii the heat generated by the devices within the casing and keep the temperature thereof working conditions.

The outer portions of the spool flanges 24 and 25 are provided with openings 120 which extend therethrough, as shown in Fig. 8; the spacing ring 28 for the inner spool flanges 24 and 25 is provided with holes or openings 121 which eatend radially therethrough, as shown in Figs. 2 and 5; and the outer end of cylindrical extension of the spool 18 is provided with radial slots or openings 122, as shown in Figs. 2, 5 and 6. he purpose of these openings 120, 121 and 122 is to permit air to move about freely within the casing under the influence of the moving parts therein for the distribution of heat generated therein, and to permit the heat to readily reach and be absorbed by the casing and its handle member.

I claim as .my invention 1. In an electric hammer, the combination of a casing carrying a part having a tool receiving opening therein, solenoids within the casing, a plunger in alinement with said opening and in operative relation tothe solenoids to be reciprocated thereby, a stop to limit the movement of the plunger in a direction away from said opening, a normally open contact making and breaking device for supplying current to the solenoids, a striking anvil movable within the casing between said opening and said plunger and adapted to be struck by the plunger and having a screw-threaded collar formed thereon, a sleeve surrounding said collar and having screw-threads engaged with the screw-threads of the collar, means operated by said sleeve when it is movedJlongitudinally by said anvil to close said device, means to prevent the anvil from turning when the sleeve is turned, and means operative turn said sleeve to thereby adjust the anvil relatively thereto and to said stop to vary the stroke of the plunger.

2. In an electric hammer, the combination oii'a casing, a solenoid spool within the easing and provided with a part having a groove therein, a key penetrating the casing and provided with parts engaging the outer and inner face thereof and holding it in place therein, said key entering said groove and preventing the spool from turning, solenoids carried by said spool, and hammer mechanism adapted to be actuated by said solenoids.

3. In an electric hammer, the combination of a casing, a solenoid spool within the easing and provided with a part having a groove therein, a key engaging the inner face of the casing and extending through the casing to and beyond the outer face thereof, a plate surrounding the outer portion of the key and engaging the outer face of the casing, he outer portion of said key being riveted against said plate to hold the key in place, and the key entering said groove and preventing the spool from turning, solenoids earned by said spool, and hammer mechanism adapted to be actuated by said solenoids.

4:, In an electric hammer, the combination of a casing, a solenoid spool therein having flanges fitted to the inner wall thereof, solenoids surrounding, said spool between its flanges and spaced from the inner wall of the casing, said flanges having air passages therein outwardly of the solenoids permitting air to pass between the solenoids and the casing and from side to side of said flanges, and hammer mechanism adapted to be actuated by said solenoids.

In testimony whereof I afiix my signature hereto.

LOUIS PAULERO. 

